Ambivalence

Algorithmic Reverb VST3 Plugin - 16-ch FDN | SAPF Absorption | ISM-ER | ADAA Saturator | 44.1-192 kHz

Ambivalence is a hard fork of Ambience 1.0.1, a professional-grade algorithmic reverb built on a 16-channel Feedback Delay Network (FDN) architecture. Developed with the JUCE 8 framework and modern C++20, it delivers lush, natural-sounding reverberation with the stability and precision demanded by professional audio production. This port adds macOS and Linux support and removes the original Windows-only build configuration.

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Table of Contents

1. System Requirements
2. Installation
3. Interface Overview
4. Algorithms
5. Normal Mode Parameters
6. Pro Mode
7. Visualizers
8. Acoustic Metrics
9. Preset Management
10. Signal Flow
11. DSP Technical Reference
12. Real-Time Safety
13. Tips & Workflow
14. Factory Presets
15. Troubleshooting
16. Credits & License

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System Requirements

Requirement	Specification
Operating System	macOS 11+, Windows 10/11 (64-bit), Linux (x86-64)
Plugin Format	VST3 / Standalone
CPU	Any 64-bit CPU (no SIMD-specific instructions)
RAM	4 GB minimum, 8 GB recommended
JUCE Version	8.0.x

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Installation

1. Build or download the latest Ambivalence.vst3 / Ambivalence.app.

2. Copy the .vst3 bundle to your VST3 directory:

   • macOS: ~/Library/Audio/Plug-Ins/VST3/
   • Windows: C:\Program Files\Common Files\VST3\
   • Linux: ~/.local/lib/vst3/

3. (Optional) Extract the factory preset pack into ~/Documents/Ambivalence/Presets/ (see Preset Management).

4. Rescan plugins in your DAW. Ambivalence appears under VST3 effects.

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Interface Overview

The UI is divided into five main zones:

• Header Bar - plugin title, EQ button, ER SOLO button, IN/OUT VU meters, and a footer showing the technical spec (16ch FDN | SAPF | ISM-ER | 44.1-192kHz).
• Algorithm Selector - 7 reverb type buttons.
• Parameter Panel - Normal Mode or EQ Mode knobs (toggles with the EQ button).
• Visualizer Area - RT60 graph (top) and Decay Curve (bottom).
• Preset Panel - preset browser with SAVE / LOAD / DELETE controls.

Header Bar Controls

Control	Description
EQ	Toggle button: switches the EQ Parameter Panel between Normal and EQ Mode.
ER SOLO	Toggle button: mutes Late Reverb so only Early Reflections are audible. Useful for tuning ER Level and Room Size.
IN / OUT	Stereo VU meters for input and output signal levels.

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Algorithms

Seven reverb topology buttons appear below the header. Selecting an algorithm resets HF Damping, LF Absorption, Diffusion, and all EQ Mode band multipliers to their defaults for that algorithm.

Algorithm	Acoustic Character	Best For
ROOM1	Small-medium rooms, ER active, Input Diffuser bypassed	Drums, percussion, tight ambience
ROOM2	Large studio / live room, ER active, Input Diffuser bypassed	Full band, orchestral tracking
HALL1	Medium concert hall, ER + Input Diffuser active	Strings, piano, vocals
HALL2	Large concert hall, ER + Input Diffuser active	Orchestral, cinematic
PLATE	EMT 140-style metal plate, ER bypassed	Vocals, snare, acoustic guitar
SPRING	Spring tank character, ER bypassed	Guitar, retro/vintage sounds
GOLDFOIL	Experimental large space, ER bypassed	Ambient, pads, special FX

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Normal Mode Parameters

Normal Mode presents 19 knobs organized into six sections: TIME, FREQUENCY, DIFFUSION, STEREO, CHARACTER, MIX, OUT EQ, and DUCKING.

TIME Section

Parameter	Range	Default	Description
PRE-DELAY	0-500 ms	10 ms	Delay before the reverb onset. Separates the dry signal from the reverb tail, creating a sense of space without muddying the attack.
ROOM SIZE	0.3-2.0	1.0	Scales all 16 FDN delay lines proportionally. Larger values create a larger perceived room. Also scales Early Reflection tap timings.
DECAY	0.1-20.0 s	1.5 s	Sets the mid-band RT60 target (500 Hz reference). The Stage 2 GEQ solver uses this as the anchor for all frequency bands.

FREQUENCY Section

Parameter	Range	Default	Description
HF DAMP	0.0-1.0	0.0	High-frequency absorption. At 0.0 the RT60 curve is flat; increasing reduces RT60 of high bands (2k-16k Hz), simulating carpet or heavy drapes. Reflected in the RT60 graph (orange curve).
LF ABSORB	0.0-1.0	0.0	Low-frequency absorption. Increasing reduces RT60 of low bands (31-250 Hz), simulating rooms with less bass build-up. Reflected in the RT60 graph.

Both default to 0.0. When a new algorithm is loaded they reset to 0.0 so the orange and gray RT60 curves are perfectly aligned.

DIFFUSION Section

Parameter	Range	Default	Description
DIFFUSION	0.0-1.0	0.7	Controls density of early reflections and tail diffusion. Low values = sparser echoes (small room); high values = smooth dense tail (large hall). Adjusts Input Diffuser Allpass gain and Nested Allpass gain within the FDN. Algorithm-specific sensitivity multipliers apply.
MOD AMT	0.0-1.0	0.25	Depth of LFO modulation applied to FDN delay times. Higher values add pitch modulation and reduce metallic resonances at the cost of mild pitch drift. Keep below 0.3 for natural sound; higher for chorus/shimmer effects.
MOD RATE	0.05-2.0 Hz	0.5 Hz	Base frequency of the BandlimitedNoise LFO. Each of the 16 FDN channels uses a unique rate multiplier (Golden Ratio Weyl sequence), so no two channels are ever synchronized.

STEREO Section

Parameter	Range	Default	Description
WIDTH	0.0-1.0	0.8	Stereo width of the reverb output. At 0.0 the reverb is mono; at 1.0 L/R are fully decorrelated. Controls three mechanisms: (1) side-component injection strength into the FDN (sideBoost = width x 1.5), (2) FDN output L/R cross-bleed (crossLeak = 1 - width), (3) ER tap left/right separation (erLeakage).

CHARACTER Section

Parameter	Range	Default	Description
ER LEVEL	0.0-1.0	0.6	Level of the Early Reflections path (ISM tap pattern), blended with the Late Reverb output. Set to 0 for a pure diffuse tail; increase for clarity and room definition.
SATURATE	0.0-1.0	0.0	Amount of ADAA saturation applied to the wet signal. Algorithm-dependent multiplier (PLATE 1.00x, SPRING 1.05x, ROOM 0.90x). Drive curve: 1 + amount^2 x 2.5. Wet mix: amount^2 x 0.7. Dry mix: 1 - amount x 0.25. At 0, saturation is completely bypassed.

MIX Section

Parameter	Range	Default	Description
WET	-60 to 0 dB	-4 dB	Wet signal level. An internal -1 dB offset is applied, so 0 dB on the knob = -1 dB effective. Smoothed sample-accurately via SmoothedValue to prevent zipper noise under automation.
DRY	-60 to 0 dB	0 dB	Dry (unprocessed) signal level. The dry path bypasses all DSP - no EQ, saturation, or limiting. Smoothed sample-accurately.

Send/return usage: Set DRY to -60 dB (silent) and control the return level with WET exclusively.

OUT EQ Section

Parameter	Range	Default	Description
LO CUT	20-500 Hz	20 Hz	High-pass filter applied to the wet path only. Linkwitz-Riley topology (1st-order IIR x 2 stages = 12 dB/oct). At 20 Hz the filter is effectively bypassed with no phase shift.
HI CUT	1k-20k Hz	20 kHz	Low-pass filter applied to the wet path only. Same Linkwitz-Riley topology (12 dB/oct). At 20 kHz, effectively bypassed.

DUCKING Section

Ducking reduces the wet signal level when the input exceeds the threshold, creating space between the dry signal and the reverb tail - particularly effective on percussive material and vocals.

Parameter	Range	Default	Description
AMOUNT	0-20 dB	0 dB	Maximum gain reduction applied to the wet signal when the input exceeds the threshold. Set to 0 to disable ducking entirely.
THRESH	-60 to 0 dB	-20 dB	Input level (peak) at which ducking begins.
ATTACK	0.5-100 ms	10 ms	Time for the ducking envelope to follow an increase in input level.
RELEASE	10-2000 ms	200 ms	Time for the gain to recover after the input drops below the threshold. Longer values prevent pumping after transients.

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EQ Mode

Press the EQ button in the header bar to reveal the EQ Mode panel. Two rows of advanced controls replace the Normal Mode rows. All EQ Mode adjustments are retained when switching back to Normal Mode - they are only reset when a different algorithm is selected.

RT60 Per Band (Row 1)

Ten knobs control a per-band RT60 multiplier for each octave band from 31 Hz to 16 kHz, applied on top of the base Decay time.

Knob	Center Frequency	Range	Default	Effect
RT 31Hz	31 Hz	0.5-2.0x	1.0x	Sub-bass reverb duration
RT 63Hz	63 Hz	0.5-2.0x	1.0x	Bass reverb duration
RT 125Hz	125 Hz	0.5-2.0x	1.0x	Low-mid reverb duration
RT 250Hz	250 Hz	0.5-2.0x	1.0x	Mid reverb duration
RT 500Hz	500 Hz	0.5-2.0x	1.0x	Mid reverb (anchor band)
RT 1kHz	1 kHz	0.5-2.0x	1.0x	Upper-mid reverb duration
RT 2kHz	2 kHz	0.5-2.0x	1.0x	Presence reverb duration
RT 4kHz	4 kHz	0.5-2.0x	1.0x	High reverb duration
RT 8kHz	8 kHz	0.5-2.0x	1.0x	Treble reverb duration
RT 16kHz	16 kHz	0.5-2.0x	1.0x	Air reverb duration

Example: set RT 31Hz to 1.6 and RT 16kHz to 0.6 for a warm, concert hall-style curve with extended bass and attenuated treble.

Tilt EQ (Row 2, left)

Three knobs provide broad RT60 tilt control across frequency groups, applied simultaneously with the per-band multipliers.

Knob	Bands Affected	Range	Description
TILT LOW	31, 63, 125 Hz	0.5-2.0x	Multiplies RT60 for all low bands at once.
TILT MID	250, 500, 1k, 2k Hz	0.5-2.0x	Multiplies RT60 for mid bands. Controls the body/core of the reverb.
TILT HIGH	4k, 8k, 16k Hz	0.5-2.0x	Multiplies RT60 for high bands. Reduce for darker reverb; increase for brighter, airier tails.

Sat Type & Out EQ (Row 2, right)

Control	Description
SAT TYPE	Selects the ADAA Saturator character: Warm, Tape, Tube, Hard (see DSP Technical Reference). Only visible in EQ Mode.
LO CUT (EQ)	Same parameter as Normal Mode LO CUT - both knobs control the same value.
HI CUT (EQ)	Same parameter as Normal Mode HI CUT - both knobs control the same value.

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Visualizers

RT60 Graph

Displays the frequency-dependent reverberation time across 10 octave bands (31 Hz - 16 kHz) on a logarithmic vertical scale.

Element	Description
Gray curve	The reference RT60 of the current algorithm preset - the "ideal" before any HF Damping, LF Absorption, or EQ Mode adjustments.
Orange curve	The actual effective RT60 after all adjustments. This is what you hear.
Dynamic Y axis	Auto-adjusts to the current maximum RT60 with smooth exponential tracking; grid lines at standard RT60 values.
Frequency labels	X-axis: 31, 63, 125, 250, 500, 1k, 2k, 4k, 8k, 16k Hz.

When an algorithm is first selected and HF/LF are at default (0.0), the orange and gray curves perfectly overlap.

Decay Curve Visualizer

A time-domain view of the reverb structure with a split time axis.

Zone	Time Range	Color	Description
ER Zone	0-200 ms	Blue	Expanded 2x zoom showing Early Reflection taps. Each tap is a 5 px bar with gradient fill and a diamond marker at the peak; the ER envelope connects all tap peaks.
Late Zone	200 ms - max	Orange	Theoretical exponential decay curve based on mid-band RT60, with a 2D gradient fill representing the Late Reverb energy envelope.
Boundary line	200 ms	Gray	Vertical separator between ER and Late zones.

The visualizer updates at 15 Hz to keep CPU usage minimal. RT60 values shown are based on the 500 Hz mid-band (cachedRT60Mid).

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Acoustic Metrics

Four metrics, computed from the actual reverb output signal in real time, appear in the lower-right of the Decay Curve panel.

Metric	Full Name	Formula	Interpretation
D50	Definition	E(0-50ms) / E(total)	Ratio of early to total energy. Values > 0.5 indicate high clarity. Low in large halls, high in small rooms.
C50	Clarity (speech)	10 log10[E(0-50ms) / E(50ms+)]	Positive values = more early energy. > 0 dB recommended for speech intelligibility.
C80	Clarity (music)	10 log10[E(0-80ms) / E(80ms+)]	Positive values favor direct sound. -2 to +4 dB is typical for music spaces.
EDT	Early Decay Time	RT60 estimated from first 10 dB	Perceptually dominant measure of reverb character; correlates with subjective "liveness".

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Preset Management

The Preset Panel is always visible in the lower-right area of the parameter section, regardless of Normal/EQ Mode state.

Preset UI Controls

Control	Description
< (PREV)	Load the previous preset in alphabetical order (wraps from first to last).
Preset Name (combo)	Drop-down of all available presets. Select to preview; click LOAD to apply.
> (NEXT)	Load the next preset in alphabetical order.
SAVE	Opens a dialog to name and save the current plugin state as a .ambpreset file. Existing names are overwritten.
LOAD	Loads the currently selected preset from the combo box.
DELETE	Deletes the currently selected preset after confirmation. Cannot be undone.

Preset File Location

All presets - factory and user-created - are stored as .ambpreset files in:

~/Documents/Ambivalence/Presets/

(Documents resolves to C:\Users\<YourName>\Documents on Windows.) The folder is created automatically on first use. Each .ambpreset file is a standard JUCE binary XML state file containing all plugin parameters.

Sharing Presets

Send individual .ambpreset files directly; recipients place them in their own Documents/Ambivalence/Presets/ folder and they appear in the browser on next plugin load. To share a complete library, ZIP the entire Presets folder.

Preset files are version-forward compatible: unknown parameters from newer versions are silently ignored and fall back to defaults.

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Signal Flow

Stage	Module	Description
1	Input Split	Stereo L/R converted to Mid/Side. Mid feeds the FDN; Side injects stereo character.
2	Input Diffuser	4-stage series Allpass filter (Hall, Goldfoil only). Diffusion gain = DIFFUSION x algorithm sensitivity (1.0 Hall, 0.5 Spring, etc.).
3	Early Reflections	ISM-based tapped delay line with algorithm-specific tap patterns. ER Level and Room Size control output. Bypassed for Plate, Spring, Goldfoil.
4	FDN (16 ch)	16-channel Feedback Delay Network with FWHT feedback matrix and sign-flip decorrelation.
4a	LFO Modulation	Per-channel BandlimitedNoise LFO modulates delay times (MOD AMT x rate multiplier).
4b	Stage 2 Absorption	10-band biquad GEQ cascade per channel, WLS-solved to match the target RT60 per band.
4c	Micro-Saturation	Pade x(27+x^2)/(27+9x^2) limiter in the feedback loop. kInScale=0.15, nearly linear.
4d	Nested Allpass	Per-channel Allpass filter for additional diffusion. Gain = apfGain x (0.6 + diffusion x 0.4).
5	Mix	ER x erLevel + Late x lateMakeupGain blended to stereo. Ducking envelope applied.
6	ADAA Saturator	Anti-Derivative Anti-Aliasing saturation (Warm/Tape/Tube/Hard). Wet path only.
7	Output EQ	LO CUT HPF + HI CUT LPF, 12 dB/oct Linkwitz-Riley. Wet path only.
8	Output Limiter	Brick-wall limiter at -0.5 dBFS. Attack 0.5 ms, Release 50 ms. Wet path only.
9	Final Mix	Wet x SmoothedWetGain + Dry x SmoothedDryGain, sample-accurate smoothing.

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DSP Technical Reference

FDN Architecture

A 16-channel Feedback Delay Network whose feedback matrix is a normalized Fast Walsh-Hadamard Transform (FWHT) with sign flipping for energy preservation and modal density. Delay times use the Nearest-Prime logarithmic distribution: a target delay time is computed by logarithmically interpolating between the min and max delay (determined by Room Size), then the nearest unused prime is selected. This guarantees:

• All 16 delay lines are mutually coprime (no shared factors).
• Delay times are distributed logarithmically (perceptually uniform spacing).
• No comb-filter clustering at any Room Size setting.

Stage 2 GEQ Absorption (SAPF)

Each of the 16 FDN channels has an independent 10-stage biquad cascade designed with the Valimaki-Liski Accurate Cascade Graphic Equalizer method. A Weighted Least Squares system is solved to find biquad coefficients approximating the target attenuation per band:

targetDb[b] = -60 x delaySamples / (fs x targetRT60[b])

HF Damping and LF Absorption modify the target RT60 before the WLS solve, creating perceptually natural roll-off at the spectral extremes.

BandlimitedNoise LFO

Each FDN channel has an independent LFO driven by a white-noise source (XOR-shift PRNG) filtered by a 1st-order IIR low-pass. The IIR cutoff is MOD RATE x rateMultiplier per channel. Rate multipliers use the Golden Ratio Weyl sequence:

angle = channelIndex x 1.6180339887
rateMultiplier = 0.80 + frac(angle) x 0.40        // range 0.80 - 1.20

No two channels share an LFO rate, preventing audible beating from periodic modulation.

ADAA Saturator

Anti-Derivative Anti-Aliasing prevents aliasing when the saturator introduces nonlinear distortion. ADAA computes the output as the finite difference of the antiderivative rather than evaluating the nonlinear function directly:

y[n] = (F(x[n]) - F(x[n-1])) / (x[n] - x[n-1])

A fallback to direct evaluation is used when |x[n] - x[n-1]| < 1e-5 (near-constant input) or at zero crossings.

Mode	Function f(x)	Antiderivative F(x)	Character
Warm	x / sqrt(1+x^2)	sqrt(1+x^2)	Symmetric soft clip (Vicanek-style). Warm, rounded odd harmonics.
Tape	x(27+x^2) / (27+9x^2)	- (no ADAA; Pade is inherently smooth)	Pade rational approximation. Tape-like transient rounding. Lightest CPU.
Tube	pos: x/sqrt(1+x^2), neg: x/sqrt(1+(2x)^2)	pos: sqrt(1+x^2), neg: (1/4)sqrt(1+4x^2)+0.75	Asymmetric - even-order harmonics (2nd, 4th). Analog warmth.
Hard	clip(x, -1, 1)	`x^2/2 (	x

Linkwitz-Riley Output EQ

Two cascaded 1st-order IIR filters with identical cutoff frequencies yield a 12 dB/oct roll-off with flat passband magnitude.

HPF: y[n] = R x (y[n-1] + x[n] - x[n-1])   where R = exp(-2*pi*fc/fs)
LPF: y[n] = (1-R) x x[n] + R x y[n-1]

L and R are processed independently through 2 cascaded stages each (4 filter states per filter type). At bypass frequencies (LO CUT <= 20 Hz, HI CUT >= 20 kHz) the filter computation is skipped entirely - zero CPU cost and zero phase shift.

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Real-Time Safety

The plugin is engineered for strict real-time audio operation, with hardening for DAW edge cases.

Measure	Details
No heap allocation on audio thread	All buffers (FDN delays, wet buffer, absorption coefficients) are pre-allocated in prepareToPlay(). No new/malloc/vector::resize() in processBlock().
Dirty-flag parameter dispatch	A DSPParams equality check prevents setParams() when nothing changed; the expensive Stage 2 WLS matrix solve (16ch x 10-band LDLT) is skipped when idle.
SmoothedValue gain changes	WET and DRY gain changes are interpolated at sample rate over 50 ms to eliminate zipper noise under automation.
ScopedNoDenormals	Applied at the start of every processBlock() to flush denormals to zero, preventing CPU spikes in feedback loops.
Sample-rate guard	A check at the start of processBlock() compares the current sample rate against the stored rate; mismatch triggers a safe internal reset.
Safe editor destruction	The editor destructor explicitly calls stopTimer(), setLookAndFeel(nullptr), and resets all APVTS attachments before destruction.
VST3 parameter sync	Internal parameter changes use setValueNotifyingHost() to keep automation state synchronized and prevent value rollback during recording.

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Tips & Workflow

Send vs. Insert Usage

• Insert (on a track): keep DRY at 0 dB, adjust WET to taste.
• Send/Return (on a bus): set DRY to -60 dB and WET to 0 dB; control the reverb level from the send amount.
• Parallel compression style: use multiple instances with different algorithms at low WET levels, blended together.

Using ER SOLO

Enable ER SOLO to hear only the Early Reflections:

• Fine-tune ROOM SIZE - listen for natural pre-echo spacing.
• Adjust ER LEVEL - hear how much definition the early reflections add.
• Verify the algorithm's ER pattern matches the intended space character.

Reading the RT60 Graph

The gray and orange curves overlap when HF DAMP = 0 and LF ABSORB = 0 (the default after loading a preset). Divergence indicates active spectral shaping:

• Orange below gray at high frequencies = HF DAMP active.
• Orange below gray at low frequencies = LF ABSORB active.
• Orange above gray = a EQ Mode RT band multiplier > 1.0 for those bands.

Plate Reverb Tips

PLATE has inverted RT60 behavior vs. room reverb - high frequencies decay longer (matching the EMT 140 metal plate). For best results:

• Use HI CUT to tame brightness if the plate sounds too metallic.
• Try Tape or Warm saturation for classic EMT 140 coloration.
• Lower DIFFUSION for a more ringy plate; raise for smoother tails.

Spring Reverb Tips

SPRING uses a 0.5 diffusion sensitivity multiplier - the DIFFUSION knob has a softer effect than Hall/Room. For the characteristic spring "boing":

• Use Tube saturation (kNeg = 2.0 adds harmonic richness).
• Increase MOD AMT for the pitch instability of a physical spring.
• Try DECAY between 1.5-3.5 s for vintage amp spring tank simulation.

Creating Large Ambient Pads

For infinite, evolving pads with GOLDFOIL:

• DECAY 8-12 s
• WIDTH 0.95, MOD AMT 0.45, MOD RATE 0.20 Hz
• DIFFUSION 0.90 for maximum diffusion
• LO CUT 60-80 Hz to remove sub-bass buildup
• In EQ Mode, reduce RT 8kHz and RT 16kHz to 0.6 for a warmer, less harsh tail

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Factory Presets

Ambivalence ships with 21 factory presets modeled after real-world acoustic spaces.

Algorithm	Preset Name	Reference Space
ROOM1	Abbey Road Studio2	Abbey Road Studio 2, London
ROOM1	Drums in a Box	Small dead studio room
ROOM1	Tracking Room	Medium tracking room
ROOM2	Abbey Road Studio1	Abbey Road Studio 1 (orchestral hall)
ROOM2	Capitol Studio A	Capitol Studios Studio A, Los Angeles
ROOM2	Skywalker Sound	Skywalker Sound, California
HALL1	Carnegie Hall	Carnegie Hall, New York
HALL1	Tokyo Opera City	Tokyo Opera City Concert Hall
HALL1	Berlin Konzerthaus	Konzerthaus Berlin
HALL2	Vienna Musikverein	Wiener Musikverein - Goldener Saal
HALL2	Boston Symphony	Boston Symphony Hall
HALL2	Concertgebouw	Amsterdam Concertgebouw
PLATE	EMT140 Vocal	EMT 140 plate - vocal setting
PLATE	EMT140 Snare	EMT 140 plate - snare setting
PLATE	Dark Plate	Dark plate, enhanced low end
SPRING	Surf Guitar	Guitar amp spring tank
SPRING	Vintage Studio	Fender-style spring tank
SPRING	Deep Tank	AKG BX-20 style deep spring
GOLDFOIL	Gothic Cathedral	Cologne Cathedral acoustic reference
GOLDFOIL	Stone Chamber	Stone underground chamber
GOLDFOIL	Infinite Space	Synthetic infinite ambient space

Key parameter values for the ROOM presets:

Preset	Decay	Size	Diff	Mod	Width	ER	Sat	Sat Type
Abbey Road Std2	0.45s	0.75	0.55	0.15	0.75	0.70	0.08	Warm
Drums in a Box	0.30s	0.55	0.40	0.10	0.65	0.80	0.05	Warm
Tracking Room	0.60s	0.90	0.65	0.20	0.80	0.65	0.10	Tape
Abbey Road Std1	1.80s	1.60	0.70	0.25	0.85	0.60	0.08	Warm
Capitol Studio A	1.40s	1.35	0.65	0.20	0.80	0.65	0.10	Tape
Skywalker Sound	2.00s	1.70	0.75	0.30	0.90	0.55	0.06	Warm

HALL presets:

Preset	Decay	Size	Diff	Mod	Width	ER	Sat	Sat Type
Carnegie Hall	1.70s	1.50	0.72	0.20	0.88	0.55	0.08	Warm
Tokyo Opera City	2.00s	1.65	0.75	0.25	0.88	0.50	0.06	Warm
Berlin Konzerthaus	2.00s	1.60	0.73	0.22	0.87	0.52	0.07	Warm
Vienna Musikverein	2.05s	1.80	0.80	0.25	0.90	0.50	0.07	Tube
Boston Symphony	1.85s	1.70	0.78	0.22	0.88	0.52	0.06	Warm
Concertgebouw	2.05s	1.85	0.82	0.28	0.92	0.48	0.06	Warm

PLATE / SPRING / GOLDFOIL presets:

Preset	Algorithm	Decay	Size	Diff	Width	Sat	Sat Type
EMT140 Vocal	PLATE	1.80s	1.00	0.85	0.85	0.12	Tape
EMT140 Snare	PLATE	1.00s	0.80	0.80	0.80	0.15	Tape
Dark Plate	PLATE	2.50s	1.20	0.88	0.88	0.10	Warm
Surf Guitar	SPRING	1.50s	0.70	0.45	0.70	0.20	Tube
Vintage Studio	SPRING	2.20s	0.85	0.50	0.75	0.18	Tube
Deep Tank	SPRING	3.50s	1.10	0.55	0.78	0.15	Tube
Gothic Cathedral	GOLDFOIL	8.00s	2.00	0.90	0.92	0.05	Warm
Stone Chamber	GOLDFOIL	4.00s	1.80	0.85	0.88	0.08	Warm
Infinite Space	GOLDFOIL	12.0s	2.00	0.95	0.95	0.04	Warm

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Troubleshooting

Problem	Likely Cause	Solution
Plugin does not appear in DAW	VST3 not in the correct folder	Confirm the .vst3 is in the VST3 directory for your OS and rescan.
No sound output	DRY and WET both at -60 dB, or routing	Check WET level; confirm the plugin is on an audio or return track with signal.
Reverb sounds metallic / ringy	DIFFUSION too low, or MOD AMT too low for PLATE/SPRING	Increase DIFFUSION. For PLATE, increase MOD AMT slightly (0.2-0.3).
Reverb too short despite high Decay	HF DAMP or LF ABSORB reducing some bands	Set both to 0.0; verify the orange curve on the RT60 graph.
Orange/gray RT60 curves misaligned at startup	HF DAMP / LF ABSORB not at 0	Reset both to 0.0, or load a fresh preset.
Preset not appearing in browser	File in the wrong folder	Confirm the .ambpreset is in Documents/Ambivalence/Presets/, then restart.
Audio dropout / CPU spike	Block size too small, or too many instances	Increase the audio buffer size in your DAW.

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Building from Source

Prerequisites

• CMake 3.22+
• A JUCE 8.0.x checkout (modules/juce_core must exist)
• A C++20 compiler (Apple Clang, GCC 12+, or MSVC 2022)

CMake

cmake -S . -B build -DJUCE_PATH=/path/to/JUCE
cmake --build build --config Release -j

JUCE is auto-detected from the project directory, build/JUCE (auto-fetched by make), $HOME/JUCE, /opt/JUCE, /usr/local/JUCE, and /Applications/JUCE if -DJUCE_PATH is not given. Build artifacts land in build/Ambivalence_artefacts/ (VST3 + Standalone).

Makefile

make -j        # release build (uses nproc / sysctl, native arch)
make install   # copies .vst3 + standalone into the per-OS plugin/application dirs
make clean

On the first build, JUCE 8 (JUCE_VERSION, default 8.0.15) is shallow-cloned into build/JUCE so the build is self-contained. Use an existing checkout with make JUCE_PATH=/path/to/JUCE. On macOS, artifacts are installed to ~/Library/Audio/Plug-Ins/VST3/ and ~/Applications; on Linux to ~/.local/lib/vst3/ and ~/.local/bin.

build/BuildInfo.h is generated from Source/BuildInfo.h.in at configure time and embeds the Git branch, commit, and dirty state.

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Credits & License

Original Ambience developer: @kijyoumusic (OTODESK) - Electronic Music, Sound Design, DSP Engineering - source repository

Framework: JUCE 8.0.x - ROLI / Raw Material Software (https://juce.com)

DSP References:

• Valimaki, V. & Liski, J. (2017). Accurate Cascade Graphic Equalizer. IEEE Signal Processing Letters.
• Vicanek, M. (2016). Matched Second Order Digital Filters.
• Schlecht, S.J. & Habets, E.A.P. (2017). On Lossless Feedback Delay Networks. IEEE Transactions on Signal Processing.
• Parker, J. et al. (2019). Modelling plate and spring reverberation using a DSP-informed deep neural network. ICASSP.
• Moorer, J.A. (1979). About this Reverberation Business. Computer Music Journal.

License: GNU Affero General Public License v3.0 (AGPLv3) - see LICENSE.

Copyright (C) 2026 OTODESK. All rights reserved.